Film-winding device.



0. P. JENKINS. FILM ,WINDING DEVICE.

APPLIOATION FILED MAY 22, 1911.

1,093,933. Patented Apr. 21', 191

.To all whom it may concern:

i (3 m 01s 5mm s tinwasnm GTQNQDISTBI "cror cotnnizu."

#Be it known] that -I,'CHAnLns Fnsrzors JENKINS, a eitizen'oftheUnitedStates, residin'g at ,Washington', in the District ofColumbia,-'have invented certain newand useful Improvements in Film-Winding Devices, of whichthe following-is a'specification,- referencebeing had'thereinto the accom anying drawing. T e general object of thisinvention is to provide. meanswhereby the minimum tension needed atanytime in winding motion picture film as it isdelivered by the expos mg orrojectin apparatus shall never be materia lyexcee ed.- v 1 It is commonto employ slippin belts to compensate for the increased rate 0 windingdue to the gradual increase in the size ofthe film roll, such beltsslipping. whenever the tension 11 on the film causes sufiicientresisb,ance of t \e drum to rotation. This resist ance to slipping is usuallyinvariable while the lever arm through which: the film tension acts isgradually increased through; the increasing diameter of the film rollupon the winding drum. It follows that if the apparatus be so made thatthe film tension when the roll is at a maximunris very-slight, so thatit may not prevent proper winding nor greatly wear the film'by drawingit strongly a ainst the teeth of the sprocket drum from w hich itusually comes and is yet sufiicient to cause slipping as much as may bedesirable, the tension will necessarily be much greater when the roll isnear a minimum. This follows since the tension actin througha shortlever arm must be increaset before an slipping will be .caused. Thisundesirab e tension greatly shortens the life ,of the film, whichisexpensive.

The present invention avoidsthis difiiculty by providing means wherebythe tension 18 automatically maintained at substantially the minimumtension sufiicient when the film roll is at a maximum.

In the accompanying drawings, Figure 1 shows in side. elevation so muchof a motion picture apparatus as is directly involvedwhen my devices areused. Fig, 2 is a plan view of the same devices.

In these figures, A represents a camera or prpjeeting a paratus whichdelivers the film.

in be woun and which is of such nature that it has a rotar shaft A, andB a windis in drum mounte upon a rotary shaft B an incloeed in casing X.The shaft B Specification of Letters tatent. Application w m 22, 1911.semi Ho. seam.

" it -Wm me retested Apr. 21, 1914.

'is driven by a belt C passing around pulleys -D and upon the shafts Aand B, re

spectively. y I .i v

' F, represents the film coming from' tle Gfan'd thence to the drum.The'roller G is mounted upon an arm I projecting from a rock-shaft Jmounted in the casing and providedwith a second arm K which has at itsfree end a roller L which rests upon the belt and is constantly ur edagainst the same by every-light spring of any suitable character,-tendmgto rock the rock-shaft in the 'properdirection. The tension of thespring is so adjusted that when the film roll is at a minimum the beltwill wind the film without slipping and will .hold it under very lighttension. As the I size of the film roll increases, each revolution windsup a greater .length of film and as the delivery of film from theapparatus A does not correspond ingly vary, the tendency is toincreasethe film tension. Any material increase of tension lifts the roller G,the spring yielding, and swings the roller L, correspondingl lesseningthe tension on'the belt so that it may sli This action occurs whateverthe size of t 1e film roll any increase of the predetermined light filmtension corresppndingly decreasing the belt tension so that the beltslips the more easily. Thus the film tension regulates the belt tension,automatically, and the film tension itself is kept at substantially thelowest point consistent with winding nearly'loose film.

It is obviously not essentiabthat the film or thebelt be deflected in apatric'ular direction from normal direction, nor that the invention, inits broader aspect, be limited to the s ecific means for governing therotation of t 6 drum by means of the film tension.

What I'c'laim is:

1. The combination with a closed .casin of a film drum mounted in thecasing wit its shaft-projecting therefrom and bearing.

an external driving pulley, a belt driving said pulley, a rock-shaftparallel to the drum 3 axis mounted in and projecting from the casin arigid arm fixed to the rockshaft wit tout the casing and provided with aroller normally. deflecting one fold of the driving belt, and a rigidarm fixed to the rock-shaft within the casin and hearing at its free enda roller parailel to the rockshaft in position, normally, for deflectingthe film passing to the drum.

2. The combination with a film delivery allel to the drum, mounted onthe free end 15 device having a rotary shaft bearing a pulof theinternal arm, a pulleymounted on the ley, of a closed casing or filmmagazine, a free end of the external arm and normally film drum mountedin the casing upon a resting upon the belt, a film; guide mounted rotaryshaft projecting from the latter, a in the top of the casing directlyabove the ulley mounted upon the projecting portion roller, and a springresisting swinging of 20 of the drum shaft, a belt operatively conthearms under tension of the film upon necting the two pulleys, -arock-shaft mountsaid roller. ed in the casingand parallel to the drum,an In testimony whereof I afiix my signature internal arm extending fromthe rock-shaft in presence of two witnesses.-

across the casing to a point below and at one CHARLES FRANCIS JENKINS.side of the vertical plane of the drum, an Witnessesz external armprojectmgfrom the rock shaft J AMES L.. CRAWFORD,

to a point alongside said belt, a roller, par ROBERT CRAIG GREENE.

